//author:dhclly
var o = console.log;
//要求 person 的type 是string
function greeter(person) {
    return "Hello, " + person;
}
var user = "Jane User";
o(greeter(user));
//error TS2345: Argument of type 'string[]' is not assignable to parameter of type 'string'.
var user2 = ["Jane User ", "Tim Ted"];
o(greeter(user2));
